Flux coated electrode and method of making the same



July 7', 1936. E, w, VARS v 2,046,981

FLUX COATED ELEGTRODE AND METHOD oF MAKING THE SAME FiledV OC. 5, 1933 Inventor:

Ethan VV.V y

His Attorneg.

Patented July 7, 1936 FLUX COATED ELEc'raoDE AND mamon or MAKING THE SAME Ethan W. Vars, Erie, Pa., assig'nor to General Electric Company, a corporation of New York Application october s, 193s, serial No. 692,348

c claim. (ci. 21asi My invention relates to arc welding electrodes.

Welding electrodes are often provided with surface coatings called fluxes which are used to improve the arcing characteristic of the electrode as well as to improve the quality of the weld metal produced thereby.

Most electrode fluxes are of an electrically nonconducting character, and if the coating on the electrode is of substantial thickness it is necessary to remove a portion thereof to adapt the electrode for use. In hand-welding an end of the electrode is bared so that welding current can be supplied thereto by means of an electrode holder and in automatic arc welding special means are l5 provided for supplying welding current through the coating, or a portion of the coating on the electrode is removed for this purpose.

It is an object of my invention to provide an electrode of improved construction to which welding current may be supplied without removing a portion of its coating or without providing special means for supplying welding current through incisions or openings produced in its coating.

More particularly it is an object of my invention to provide an electrode coated with strands of flux impregnated iibrous material arranged between iln-like projections forming an integral part of the electrode and serving to hold the fibrous material in place on the electrode as well as to conduct welding current into the electrode;

It is a further object of my invention to provide convenient and economical methods of fabricating electrodes in accordance with my invention.

Further objects of my invention will become apparent from the following description taken in connection with the accompanying drawing, Figs. 1 and 3 of which illustrate electrodes embodying my invention, and Figs. 2 and 4 of which diagrammatically represent one method and apparatus for making each of said electrodes.

According to my invention a small amount of the surface metal of the electrode is raised to form projections which extend through the ux coating applied thereto. Thus, for example, in

45 Fig. 1 a portion of the surface metal of an electrode I is struck up to form fin-like projections 2 which extend through the flux coating 3 applied to the surface of the electrode. In the construction illustrated, this coating 2 comprises a helical wrapping of strands of ux impregnated fibrous material I which is arranged between the projections 2. It will be noted that the projections extend parallel to the wrapping and are separated from one another circumferentially as well 5 as lengthwise of the electrode. These projections serve as conductors for the welding current and also serve to reinforce the flux coating against compressive forces. When using electrodes in accordance with my invention for hand welding, it is not necessary to` use's'hort lengths as in the past, since the welding current may be supplied to the electrode ,at any point along its length. Neither is it necessary in automatic welding to use means for removing a portion of the surface coating of the electrode or for making incisions or openings in the flux coating for supplying welding current to the electrode.

In Fig. 2, I have diagrammatically illustrated apparatus for manufacturing an electrode such as illustrated in Fig. 1. This machine operates as follows: Electrode material 5 is withdrawn from a reel 6 by propelling and straightening rolls l which may also serve to time the cutting strokes of the projection raising tools 8. 9 represents a guide which centers the wire relative to the tools 8 and also serves to absorb the cutting force from .these tools. The tools 8 are preferably grouped about the wire and arrangedto strike the wire according to predetermined timing which automatically locates contacts 2 in a predetermined helical pattern .about and along the wire. The contacts 2 are raised far enough above the surface of the wire so that they will project beyond the iiux coating applied thereto. An initial ux coating is applied to the wire by discharging liquid flux I0 on to the wire. This iluxis supplied through a nozzle Il and the surplus material is collected by a receiver I2 from which it is withdrawn and again supplied to the nozzle II. A Wrapping 4 of flbrous material is then applied to the wire and another coating of liquid flux applied to the wrapped wire by means of another nozzle .|3. The surplus material supplied by this nozzle is collected by another receiver Il. The flux coated wire is then passed through a container I5 in which there is a suitable drying material I6 which acts to set the ux. The openings in the container I5 through which the covered wire passes may also be used for sizing the iiux coating. Means II may also be provided for sizing the contacts 2 to form an electrode of predetermined diameter which is then coiled on a reel I8.

The stranded ux impregnated brous material may also be applied to the electrode along its length, as illustrated in Fig. 3. In such case the flux material I9 is placed between parallel rows of longitudinally disposed iin-like projections 20 forming an integral part oi the electrode 2I. The flux material 3 may be held in place on the electrode by the adhesive character of the nur. even when wet, but ll prefer also to provide a binding string or strings 22 for holding it in place thereon. Most uxes when dry will adhere to the electrode and the use of a binding string or strings will hold the fibrous ux impregnated material in place on the electrode until the hun dries.

Apparatus for manufacturing the electrode of Fig. 3 is diagrammatically illustrated in Fig. d. In the apparatus there illustrated electrode wire 23 is withdrawn from a reel 2d by feed rolls 25. These feed rolls are grooved so that oppositely disposed pairs completely encircle the electrode.

The groove of eachgwheel is provided with op positely disposed projections which squeeze up from the surface,material of the electrode a. rounded n-like projection such as 2@ illustrated in Figs. 3 and d. The electrode wire is then coated with a ux material 2l supplied through a nozzle 28. A coating of fibrous material i@ is then applied to the electrode from reels 2i) through the agency of a nozzle dit, which uniformly distributes this brous material about the surface of the electrode wire. Another coating of ux material 2l is then applied to the coated Wire through another nozzle Si. The surplus'of the ux material supplied through nozzles 283 and 3l is collected by receivers d?? from which it is again supplied to the nozzles 2li and 3l. The flux impregnated surface coating is then wrapped with a binding cord or cords 22 which is supplied from a reel 33 located on a flier dll which is rotated about the axis of the coated wire by means of af belt 35 and pulley 3b. Since the speed of fabricating the electrode may be limited by the speed at which a single binding or wrapping cord 22 can be applied thereto, this dimculty may be su". nated by using a number of wrapping cords in parallel. After the electrode has been thus wrapped it may in some casas be necessary to dry the ux material on the electrode or to use a flux setting powder such as employed in the machine of Fig. 2. llt is also to be understood that the electrode may be sized by passing it through a suitable opening as in the machine of Fig. 2. The finished electrode is then coiled upon a reel 3l.

'I'he practical advantage of the method last described for raising nii-like projections on the electrodes lies in the high speed at which the operation can be carried out as comparedto the operation of producing barbs or pronglike projections on the surface of the electrode such as described above in connection with Figs. l and 2. Furthermore, the shape of the projection produced by squeezing up a portion of the surface metal of the electrode is better adapted as a contact and as a reinforcement for the ux coat= ing than is the barbed or pronglilre projections of the electrode illustrated in Fig. l. 'llhe elece trode is also safer to handle due to the absence of sharp points characteristic of the electrode illustrated in Fig. l.

f It is to .be noted that the projections on the electrode when formed Kin accordance with invention constitute but a small amount of the total metal in the electrode. lit is therefore pos sible to maintain the desired relation between the cross-sectional area of the electrode and the cross-sectional area of the hun without in amasar Wire is the most economical shape which can be produced and a-modied round wire is consequently of the greatest practical value as a base for the projections. It is to be understood, however, that wires of other shapes may be employed 5 Without departing from my invention.

The 1in-like projections on the electrode may be raised to any reasonable height in relation to the coating applied to the electrode. It is desirable that the projections extend through the ux for by employing this construction they will be self-clearing due to the friction exerted thereon when passing through the current supplying means forming part of the welding machine. If the height of the projection is just equal to the thickness of the flux coating, it is liable to gather iiux on its contacting tip, and this will be a potential source of arcing which may damage the means provided in the Welding machine for supplying welding current to the electrode. Ilhese projections may be raised at the same time that the coating is applied to the electrode, or they may be raised at the time the wire is rolled or formed in the mill. It is desirable to form these projections at the same tim'e that the flux is applied so that their height may be regulated in accordance with the thickness of the ux applied to the electrode.

Heavy coated electrodes may be made in accordance with my invention at agreatly reduced cost as compared with most other methods of fabricating heavy coated electrodes. With regard tothe matter of economy it is also to be noted that no part of the nur.. coating on the electrode is wasted when using the electrode, and 35 that when hand-welding, it is not necessary to operate with electrodes of extremely short lengths which results in a considerable loss due to the discarded end-portions which cannot be used for welding.

ln describing my invention I have referred to electrodes having a surface coating of ux impregnated fibrous material. It is to be understood, of course, that the invention is not limited to electrodes of this construction, since other flux coatingsmay also be employed without departing from my. invention.

What ll claim as new and desire to secure by Letters Patent of the United States, is:

l. An arc welding electrode having a coating of strands of ux impregnated brous material through which extend n-like projectionsforming an integral part of said electrode.

2. An arc welding electrode coated with a helical Wrapping of flux impregnated brous material arranged between iin-like projections extending parallel to said wrapping and separated from one another circumferentially as well as lengthwise of said electrode.

l 3. An arc welding electrode coated with strands of ilux impregnated fibrous material arranged between parallel rows of fin-like projections forming part of said electrode and extending through said coating.

d. An are Welding electrode coated with strands 65 of flux impregnated nbrous material arranged between parallel rows of staggered iin-like projections extending along said electrode and form.- ing a part thereof.

5. The method of making a uxed welding electrode which comprises raising small amounts of the surface metal of the electrode to form nlike projections, applying strands of brous material to said electrode between said projections, and impregnatiug said strands with ux to form a coating through which said projections extend.

6. The method of making a uxed welding electrode which comprises cutting and raising helicaily disposed fin-like projections from the 5 surface metal o! the electrode, applying a. helical wrapping oi fibrous material to said electrode between said projections. ux impregnating said wrapping, and sizing said projections to form an electrode of predetermined diameter in which said projections extend through the coating formed by said iiux impregnated wrapping.

ETI-IAN W. VARS. 

